Abstract: A turbomachine including a shaft, a bearing for supporting the shaft and including an outer ring, and a support for the bearing, the support having a flange to which the outer ring is fastened by fasteners, is provided. Each fastener includes a fastener bolt and a nut screwed together. The turbomachine further includes, for each fastener, a position-retention device for retaining the bolt, and suitable for retaining the bolt in a position that is stationary relative to the bearing support or the outer ring, even in the absence of the nut. The head of the fastener bolt and the position-retention device may be of small dimensions, thereby enabling the fastening of the flange to the bearing support to be optimized, and in particular enabling the weight of the fastening to be optimized. A method of mounting the bearing of the turbomachine is also provided.

Abstract: A dual-flow turbine engine including: a fan rotatably mounted on a fan shaft and a stationary structural element, the fan shaft and the structural element being connected to one another at an upstream bearing and at a downstream bearing via an upstream bearing bracket and a downstream bearing bracket, respectively; and a decoupling device surrounding the fan shaft, and including a set of attachment screws joining the downstream bearing bracket to the structural element and a set of fusible screws joining the upstream bearing bracket to the downstream bearing bracket. At least some of the fusible screws are arranged between at least some of the attachment screws over a single circumference surrounding the fan shaft.

Abstract: A turbojet engine including an intermediate casing including radial arms and a driveshaft for a gearbox for auxiliary machines of the turbojet engine, the driveshaft mounted in a radial arm, the radial arm including an intermediate bearing supporting the driveshaft, the intermediate bearing including plural rolling bearings supporting the driveshaft, the driveshaft including a first shaft element connected at one end to a mechanism providing mechanical transmission to an engine shaft of the turbojet engine, and a second shaft element connected at one end to a mechanism providing mechanical transmission to the box. The first shaft element and the second shaft element are linked by a connection including plural splines. A single plane transversely passes through the plural splines and the plural rolling bearings.

Abstract: A device for uncoupling a bearing carrier in a turbomachine, the bearing carrier including an upstream part and a downstream part including a plurality of upstream orifices respectively facing a plurality of downstream orifices. The uncoupling device includes rupture screws each passing through an upstream orifice and a downstream orifice, and at least a mechanism for double centering of a rupture screw with respect to the upstream orifice and to the downstream orifice respectively. The mechanism for double centering is independent of the upstream and downstream parts of the bearing carrier and of the rupture screw, and is configured to collaborate with the upstream part of the rupture screw such that when the rupture screw breaks, the upstream part carries with it the mechanism for double centering. A turbomachine can include such an uncoupling device.

Abstract: System for securing two tubular components (20, 22) one in the other, carrying a roller bearing (14) for holding the latter in position. Said system (15) includes a forcing nut (25) mounted inside the coaxial components and axially abutting against the first component after screwing-in of the second component, and a locking pin (26), for preventing unscrewing of the nut, arranged between the latter and the first component. Advantageously, the system further comprises a cylindrical sleeve (51) arranged between the pin (26) and the first component (20), being secured axially relative to the latter, and including an axial stop (52) against which the pin is applied, and first and second means (57, 58, 60, 61, 62) for linking the pin and the first component in rotation, respectively, with the sleeve.

Abstract: A guide shaft bearing including an internal ring mounted on a cylindrical contact surface of a shaft and a device for the axial locking of the ring including a ring mounted sliding on the cylindrical contact surface and an annular rib made of shape memory material mounted in two annular grooves of the cylindrical contact surface and of the ring is disclosed. The annular rib is able to expand radially by shape memory effect when it is subjected to a temperature greater than a transition temperature of its material to pass to a locking position of the ring on the cylindrical contact surface.

Abstract: A twin fan turbomachine with two contrarotating fans, one upstream and one downstream, driven by two contrarotating coaxial shafts each of which connects one fan impeller to at least one low-pressure turbine impeller located downstream, the downstream fan impeller being connected by its downstream part to its drive shaft.

Abstract: An aeroengine fan casing is made of composite material comprising fiber reinforcement densified by a matrix. The casing (10) is secured to at least one ring (24) or ring sector that is situated on the inside face of the casing and that is mechanically connected to an equipment fastener part (26) that is situated on the outside face of the casing, in particular for fastening an accessory gearbox.

Abstract: A gas turbine engine including a shaft, a bearing, a coupling supported by the bearing is disclosed. The shaft is engaged by an end trunnion inside the coupling and fixed to the coupling by a cylindrical nut. The engine is characterized in that the nut is in axial abutment in a first direction against the coupling and the trunnion is screwed onto the nut. A slotted stop ring housed in an annular groove of the nut forms an axial abutment in the direction opposing the first direction, so as to allow the removal of the trunnion from the coupling by unscrewing the nut.

Abstract: A turbomachine comprising high- and low-pressure compressor shafts guided in bearings isolated from an internal enclosure by a sealing end plate, and radial pressurization tubes connecting the enclosure to an air passage passing through the intermediate casing, the ends of these tubes being engaged in sealed manner in radial ducts of the intermediate casing and in radial chimneys of the sealing end plate, the chimneys being of a length is sufficient to enable the ends of the tubes to be moved in translation therein between a service position and a mounting position for the tubes.

Abstract: The relief device is designed to divert a portion of a main flow toward a by-pass flow in a turbojet that includes a main flow stream, a by-pass flow stream and an intermediate casing. The relief device includes inner openings of the inner shroud, outer openings of the outer shroud, a relief circuit connecting the inner openings to the outer openings, and a blanking device capable of opening and closing the relief circuit. The relief circuit includes upstream holes of the intermediate casing, downstream holes of the intermediate casing, and an annular channel defined between the intermediate casing, the outer shroud and a connecting partition. The connecting partition rests on the intermediate casing so as to encompass the downstream holes of the intermediate casing in the annular channel and resting on the outer shroud so as to encompass the outer openings of the outer shroud in the annular channel.

Abstract: An accessory gear box driveshaft in a turbojet engine with intermediate casing, designed to be mounted in a radial arm of the intermediate casing is disclosed. The shaft is mechanically connected, at a first end, to a an engine shaft of the turbojet engine, and is mechanically connected, at a second end, to a gear box. The shaft includes a bevel gear between the two ends, to provide mechanical transmission to an additional accessory. This shaft is notable in that, together with the gear, it is contained in a case forming an oil circuit sealed against the arm. The accessory includes a drive shaft collaborating with the gear of the transmission shaft and forming a modular assembly therewith.

Abstract: A turbomachine including a shaft, a bearing for supporting the shaft and including an outer ring, and a support for said bearing, the support having a flange to which the outer ring is fastened by fasteners; each fastener comprising a fastener bolt and a nut screwed together; the turbomachine also including for each fastener, position-retention means for retaining the bolt, and suitable for retaining the bolt in a position that is stationary relative to the bearing support or the outer ring, even in the absence of the nut. The head of the fastener bolt and the position-retention means may be of small dimensions, thereby enabling the fastening of the flange to the bearing support to be optimized, and in particular enabling the weight of said fastening to be optimized. The invention also provides a method of mounting said bearing of the turbomachine.

Abstract: A turbomachine fan rotor including a disk carrying blades with roots that are engaged in axial grooves of the disk, a spacer being interposed between the bottom of each groove and the corresponding blade root, the spacer including at its upstream end a nib for retaining the blade root, the nib including a downstream abutment face against which the upstream end of the blade root bears in event of a violent force being applied thereto, the abutment face being oblique relative to the axis of rotation of the rotor.

Abstract: A system for attaching the end of a shaft of a gas turbine engine engaged inside a coupling supported by a bearing is disclosed. The system includes a nut with a first thread which is screwed into the shaft and a second thread which is screwed to the coupling. Advantageously, the screw pitches of the two threads of the nut are reversed relative to one another so as to form an adjusting nut.

Abstract: A system for fastening the end of a gas turbine engine shaft engaged inside a sleeve supported by a bearing is disclosed. The system includes a nut that is screwed at one end inside the sleeve, and is connected by a split annular ring with the shaft at the other end.

Abstract: Guide shaft bearing comprising an internal ring mounted on a cylindrical contact surface of a shaft and means for the axial locking of the ring comprising a ring mounted sliding on the cylindrical contact surface and an annular rib made of shape memory material mounted in two annular grooves of the cylindrical contact surface and of the ring, the annular rib being able to expand radially by shape memory effect when it is subjected to a temperature greater than a transition temperature of its material to pass to a locking position of the ring on the cylindrical contact surface.

Abstract: A turbomachine including a shaft guided in an upstream bearing and a downstream bearing, the upstream bearing being carried by a first annular support that is fastened by bolts to a casing via a second annular support that carries the downstream bearing, wherein the ends of the fastener bolts are covered by an annular cover sealingly fastened to the second support or to the casing.

Abstract: A turbomachine comprising high- and low-pressure compressor shafts guided in bearings isolated from an internal enclosure by a sealing end plate, and radial pressurization tubes connecting the enclosure to an air passage passing through the intermediate casing, the ends of these tubes being engaged in sealed manner in radial ducts of the intermediate casing and in radial chimneys of the sealing end plate, the chimneys being of a length is sufficient to enable the ends of the tubes to be moved in translation therein between a service position and a mounting position for the tubes.

Abstract: A twin fan turbomachine with two contrarotating fans, one upstream and one downstream, driven by two contrarotating coaxial shafts each of which connects one fan impeller to at least one low-pressure turbine impeller located downstream, the downstream fan impeller being connected by its downstream part to its drive shaft.